Buggy code:
public char [ ] [ ] taskPriorites = null ; public boolean isTaskCaseSensitive = true ; public boolean reportDeprecationInsideDeprecatedCode = false ; public boolean reportDeprecationWhenOverridingDeprecatedMethod = false ; public boolean reportUnusedParameterWhenImplementingAbstract = false ; public boolean reportUnusedParameterWhenOverridingConcrete = false ; public boolean reportUnusedDeclaredThrownExceptionWhenOverriding = false ; public boolean reportSpecialParameterHidingField = false ; public int reportInvalidJavadocTagsVisibility = ClassFileConstants . AccPrivate ; public boolean reportInvalidJavadocTags = true ; public boolean reportInvalidJavadocTagsDeprecatedRef = true ; public boolean reportInvalidJavadocTagsNotVisibleRef = true ; public int reportMissingJavadocTagsVisibility = ClassFileConstants . AccPrivate ; public boolean reportMissingJavadocTagsOverriding = false ; public int reportMissingJavadocCommentsVisibility = ClassFileConstants . AccPublic ; public boolean reportMissingJavadocCommentsOverriding = false ; public boolean inlineJsrBytecode = false ; public boolean docCommentSupport = false ; public boolean suppressWarnings = true ; public CompilerOptions ( ) { } public CompilerOptions ( Map settings ) { } public Map getMap ( ) { } public int getSeverity ( long irritant ) { } public String getSeverityString ( long irritant ) { } public String getVisibilityString ( int level ) { } public void set ( Map optionsMap ) { } public String toString ( ) { } void updateSeverity ( long irritant , Object severityString ) { } public static long versionToJdkLevel ( Object versionID ) { } public static String versionFromJdkLevel ( long jdkLevel ) { } public static String [ ] warningOptionNames ( ) { } public static String warningTokenFromIrritant ( long irritant ) { } public static long warningTokenToIrritant ( String warningToken ) { if ( ( warningToken == null ) || ( ( warningToken . length ( ) ) == 0 ) ) return 0 ; switch ( warningToken . charAt ( 0 ) ) { case 'a' : if ( "all" . equals ( warningToken ) ) return - 1L ; if ( "assertIdentifier" . equals ( warningToken ) ) return CompilerOptions . AssertUsedAsAnIdentifier ; break ; case 'b' : if ( "boxing" . equals ( warningToken ) ) return CompilerOptions . Autoboxing ; break ; case 'c' : if ( "constructorName" . equals ( warningToken ) ) return CompilerOptions . MethodWithConstructorName ; if ( "conditionAssign" . equals ( warningToken ) ) return CompilerOptions . AccidentalBooleanAssign ; if ( "charConcat" . equals ( warningToken ) ) return CompilerOptions . NoImplicitStringConversion ; break ; case 'd' : if ( "deprecation" . equals ( warningToken ) ) return CompilerOptions . UsingDeprecatedAPI ; if ( "dep-ann" . equals ( warningToken ) ) return CompilerOptions . MissingDeprecatedAnnotation ; break ; case 'e' : if ( "emptyBlock" . equals ( warningToken ) ) return CompilerOptions . UndocumentedEmptyBlock ; if ( "enumIdentifier" . equals ( warningToken ) ) return CompilerOptions . EnumUsedAsAnIdentifier ; if ( "enumSwitch" . equals ( warningToken ) ) return CompilerOptions . IncompleteEnumSwitch ; break ; case 'f' : if ( "fieldHiding" . equals ( warningToken ) ) return CompilerOptions . FieldHiding ; if ( "finally" . equals ( warningToken ) ) return CompilerOptions . FinallyBlockNotCompleting ; if ( "finalBound" . equals ( warningToken ) ) return CompilerOptions . FinalParameterBound ; break ; case 'i' : if ( "intfNonInherited" . equals ( warningToken ) ) return CompilerOptions . IncompatibleNonInheritedInterfaceMethod ; if ( "indirectStatic" . equals ( warningToken ) ) return CompilerOptions . IndirectStaticAccess ; if ( "intfAnnotation" . equals ( warningToken ) ) return CompilerOptions . AnnotationSuperInterface ; break ; case 'j' : if ( "javadoc" . equals ( warningToken ) ) return ( ( CompilerOptions . MissingJavadocComments ) | ( CompilerOptions . MissingJavadocTags ) ) | ( CompilerOptions . InvalidJavadoc ) ; break ; case 'l' : if ( "localHiding" . equals ( warningToken ) ) return CompilerOptions . LocalVariableHiding ; break ; case 'm' : if ( "maskedCatchBlock" . equals ( warningToken ) ) return CompilerOptions . MaskedCatchBlock ; break ; case 'n' : if ( "nls" . equals ( warningToken ) ) <START_BUG> return CompilerOptions . AssertUsedAsAnIdentifier ; <END_BUG> if ( "noEffectAssign" . equals ( warningToken ) ) return CompilerOptions . NoEffectAssignment ; if ( "null" . equals ( warningToken ) ) return CompilerOptions . NullReference ; break ; case 'o' : if ( "over-ann" . equals ( warningToken ) ) return CompilerOptions . MissingOverrideAnnotation ; break ; case 'p' : if ( "pkgDefaultMethod" . equals ( warningToken ) ) return CompilerOptions . OverriddenPackageDefaultMethod ; break ; case 'r' : if ( "restricted" . equals ( warningToken ) ) return ( CompilerOptions . ForbiddenReference ) | ( CompilerOptions . DiscouragedReference ) ; break ; case 's' : if ( "syntheticAccess" . equals ( warningToken ) ) return CompilerOptions . AccessEmulation ; if ( "staticReceiver" . equals ( warningToken ) ) return CompilerOptions . NonStaticAccessToStatic ; if ( "serial" . equals ( warningToken ) ) return CompilerOptions . MissingSerialVersion ; if ( "semicolon" . equals ( warningToken ) ) return CompilerOptions . EmptyStatement ; break ; case 't' : if ( "typeHiding" . equals ( warningToken ) ) return CompilerOptions . TypeParameterHiding ; break ; case 'u' : if ( "unusedLocal" . equals ( warningToken ) ) return CompilerOptions . UnusedLocalVariable ; if ( "unusedArgument" . equals ( warningToken ) ) return CompilerOptions . UnusedArgument ; if ( "unchecked" . equals ( warningToken ) ) return CompilerOptions . UncheckedTypeOperation ; if ( "unusedImport" . equals ( warningToken ) ) return CompilerOptions . UnusedImport ; if ( "unusedPrivate" . equals ( warningToken ) ) return CompilerOptions . UnusedPrivateMember ; if ( "unqualifiedField" . equals ( warningToken ) ) return CompilerOptions . UnqualifiedFieldAccess ; if ( "unusedThrown" . equals ( warningToken ) ) return CompilerOptions . UnusedDeclaredThrownException ; if ( "uselessTypeCheck" . equals ( warningToken ) ) return CompilerOptions . UnnecessaryTypeCheck ; if ( "unnecessaryElse" . equals ( warningToken ) ) return CompilerOptions . UnnecessaryElse ; break ; case 'v' : if ( "varargs" . equals ( warningToken ) ) return CompilerOptions . VarargsArgumentNeedCast ; break ; case 'w' : if ( "warningToken" . equals ( warningToken ) ) return CompilerOptions . UnhandledWarningToken ; break ; } return 0 ;

Fix:
return CompilerOptions . NonExternalizedString ;